Renaissance Child Safe Wheel & Chain Release Roman Blind KitRenaissance Child Safe Wheel & Chain Release Closed Cassette Roman Blind Kit. The pre assembled kit is an essential time saver as all kits are supplied ready assembled and corded with a bottom weight bar. The Wheel & Chain Release Housing is installed into the headrail and is screwed securely into place. Remove the orange spacer from the Housing and with your chain of choice wrapped around the specially designed pivot wheel and push neatly into place