12 - 40MM X 450MM Heatsinks. These are heatsinks I specifically ordered for the LED strips to build a frame out of, but they can be cut to length and used for any purpose you may need a heatsink for.
Some people are even cutting them and using them on their MeanWell HLG power supplies to keep them cooler. All you need is a piece of 1/2 aluminum angle on each side and you can space your LED strips how you want them to be.
See the pics for an example. They are 40 x 450mm(approximately 17) and hold the 30 x 400mm strips perfectly(see pic). It is very easy to attach the strips to the heatsink with thermal tape, heatsink plaster, or, if you like, drill the holes and use self-tapping screws.
It is for demonstration of how the strips fit the heatsinks and what you can build only. The item "(12) 40 x 450mm heatsink for Samsung lm561c 301b led quantum grow board strip" is in sale since Tuesday, January 7, 2020.This item is in the category "Home & Garden\Yard, Garden & Outdoor Living\Hydroponics\Grow Lighting & Accessories\Grow Light Accessories". The seller is "ucandewit" and is located in Erwin, Tennessee. This item can be shipped to United States, Canada, United Kingdom, Denmark, Romania, Slovakia, Bulgaria, Czech republic, Finland, Hungary, Latvia, Lithuania, Malta, Estonia, Australia, Greece, Portugal, Cyprus, Slovenia, Japan, China, Sweden, South Korea, Indonesia, Taiwan, South africa, Thailand, Belgium, France, Hong Kong, Ireland, Netherlands, Poland, Spain, Italy, Germany, Austria, Bahamas, Israel, Mexico, New Zealand, Philippines, Singapore, Switzerland, Norway, Saudi arabia, Ukraine, United arab emirates, Qatar, Kuwait, Bahrain, Croatia, Malaysia, Brazil, Chile, Colombia, Costa rica, Dominican republic, Panama, Trinidad and tobago, Guatemala, Honduras, Jamaica, Antigua and barbuda, Aruba, Belize, Dominica, Grenada, Saint kitts and nevis, Saint lucia, Montserrat, Turks and caicos islands, Barbados, Bangladesh, Bermuda, Brunei darussalam, Bolivia, Ecuador, Egypt, French guiana, Guernsey, Gibraltar, Guadeloupe, Iceland, Jersey, Jordan, Cambodia, Cayman islands, Liechtenstein, Sri lanka, Luxembourg, Monaco, Macao, Martinique, Maldives, Nicaragua, Oman, Peru, Pakistan, Paraguay, Reunion, Viet nam, Uruguay, Russian federation.