that depends, not all wheels are the same
tracy o brien 6" aluminum wheel and 4.00-6 tire without tube if you use tubeless kit is little under 4 lbs,i have wheels about the same size on mine and they are 3.5 lbs each ,but these wheels are unavailable to by in usa ,I have three spares
another wheel which is often used is azusalite 6" ,but you have to use tube and with tire the weight is close to 4.5 lbs .probably lightest wheel is tracy o brien it is same as hegar ,or you can use vanK rims which is same think only difference its cost lot less than hegar