Both Autel IM608 and OBDSTAR X300 DP Plus will do Chevy Silverado 2021 blade and smart keys. Autel IM508 / IM608 does not have the 2021 Silverado in the coverage list. The list is not 100% correct. Autel adds new CAN FD models smart keys in July 2021. Yukon 2021 proximity Sierra 2021 proximity Escalade 2021 proximity Tahoe 2021 proximity Silverado 2021 proximity Suburban 2021 proximity Autel Im608 Silverado 2021 We have customers did 2021 Silverado both with and without adapter. 1). We have customer did a 2021 Silverado no adapter is needed. It was smart fob key. im508 pulled it from the bcm no problem. Still good on Silverados. Keyed or proximity. Sierra should be the same. 2). We had another customer just used the CAN FD adapter and it works great. On a 2021 Silvarado, push to start. Used manual selection, under 2020. prox key with the Can FD, and it pulled pin in less then a min, then took 10 for security granted, and key went right in. I was a...